Civil Engineering - Strength of Materials - Discussion


In a loaded beam, the point of con-traflexture occurs at a section where

[A]. bending moment is minimum
[B]. bending moment is zero or changes sign
[C]. bending moment is maximum
[D]. shearing force is maximum
[E]. shearing force is minimum.

Answer: Option B


No answer description available for this question.

Raghavendra said: (Jun 22, 2013)  
Meaning of contraflexure is contra opposite and flexure means bending totally it means zero bending moment or change in sign of bending moment.

Gaurav said: (Sep 9, 2013)  
What is the difference between point of inflection and contraflexure?

Yashu Singh said: (Sep 25, 2013)  
If bending moment sign change at a section then such as a point is called contraflexure.

Sachin said: (Oct 22, 2013)  
Point of inflection - point where SF change its sign in SFD.

T.KUMARESAN said: (Aug 16, 2014)  
Inflection - SF change.
Contraflexure - BM change.

Namrata said: (Aug 23, 2014)  
Contraflexure is the point where bending moment changes its sign, and the value of it is zero.

Vinayak said: (Oct 11, 2014)  
Point of inflection & point of contraflexure both are same.

Stan said: (Nov 16, 2014)  
When BM changes sign in a BMD.

Iswarya said: (Jan 29, 2015)  
When bending moment is zero shear force is maximum.

S.Basavachetan said: (Feb 7, 2015)  
In BM diagram sign changes from +ve to -ve & becomes zero is called point of contraflexure.

Milton Singh said: (Jun 29, 2015)  
Point of inflection is where shear force changes sign.

Point of contraflexure is where bending moment changes sign.

Gulshan Kumar said: (Jul 7, 2015)  
Point of inflection is that point where any curve changes it's sign. But point of contraflexure is that point where bending moment changes it's sign.

Venkat said: (Aug 31, 2015)  
In which beams con-traflexture points occur?

I need maximum number of con-traflexture points for cantilever, simply supported, propped, overhanging and fixed beams.

Niraj Kumar Yadav said: (Oct 22, 2015)  
Contraflexture means opposite bending means conraflexture is which point these bending is zero there don't any typical bending created its than possible that all these signs of these beam are opposite and beam edge are long.

Charan Sai said: (Dec 4, 2015)  
Note not to confuse between point of contraflexure and point of inflection. Many saying they are same but they are not actually same, they both are different.

Kabang said: (Feb 10, 2016)  
Thanks everyone for sharing your knowledge.

Deepak said: (Mar 1, 2016)  
#POC is that where the shear force change its sign not bending moment and in this case bending moment is usually the maximum.

Deepak Jaiswal said: (Mar 4, 2016)  
Point of Contraflexure is point on bending moment diagram and point of inflection is point on the deflected shape.

POC is the point where bending moment changes sign and POI is the point where curve changes sign (EXP- convex to concave).

Jitendra Malviya said: (Jun 22, 2016)  
A point of contraflexure is the point where the BM curve intersects zero line.

Prakash Keskar said: (Aug 2, 2016)  
Point of contra flexure is the point where bending moment is zero.

Sunita Das said: (Sep 1, 2016)  
The point of contra flexure means where BM changes its sign.

Phani said: (Dec 23, 2016)  
Point of inflection is for elastic curve.

Radhe said: (Jan 14, 2017)  
Inflection : If we extent the line from the point of cotrflexure to the load beam, then that point on loaded beam is point of Inflection.

Ashish (IIT,Pawai) said: (Mar 4, 2017)  
Inflection is a point where the curvature of the bending moment changes the sign not S.F its wrong.

Contaflexure is pt where B.M changes sign.

Sai said: (May 13, 2017)  
POC means BM change its sign.

POI means BM is zero.

Ashu said: (Jul 20, 2017)  
The Point of inflextion is used in case of the elastic curve. Where the curve changes from concave to convex (or) convex to concave.

The contraflexture used in case of B.M.D where the B.M change its sign.

Ajith said: (Aug 22, 2017)  
How many points of Contra flexure for simply supported beam overhang at one end only?

AVI PANDEY said: (Sep 13, 2017)  
Will point of contraflexure be on support?

Er. Bazrul Hasan said: (Dec 5, 2017)  
Generally, Point of cocontra flexure Point of inflexion these are same, inflexion is the word of math which means curve change own sign and contraflexure is the word from Mechanics.

Rahul Kumar Singh said: (Jun 16, 2018)  
Point of inflection is for elastic curve whereas point of contraflexure is for Bending moment.

N.Akhil said: (Aug 19, 2018)  
The point of inflection is BM is 0.

The point of contraflexure is BM is 0 and change its sign.

That is all point of contraflexures are the point of infletion but all point of infletion are not point of contraflexure.

Hope you understand.

Ankit Verma said: (Sep 28, 2018)  
Inflection point ----- it is the point, where S.F is 0 or change its sign.

Contraflexure point ----it is the point, where B.M is 0 or change its sign.

Govind Kalke said: (Jan 27, 2019)  
Bm diagram going to change its sign.

Shaswat said: (Jun 16, 2019)  
Contraflexure means the point where BM changes sign or becomes 0.

Inflection means the point in the beam where the deflected shape changes, either from hogging to sagging or saaging to hogging.

Siddharth Singh Lamba said: (Nov 21, 2019)  
If a moment work on a simply supported bean then what is the shape of s.f.d and b.m.d?

Sneha said: (Oct 27, 2020)  
POI are the points where bending moment equals zero.
POC are the points where bending moment changes the sign.

So, all POC are POI, but all POI are not POC.

Sneha said: (Oct 27, 2020)  
@siddhardth sigh lamba.

It completely depends on where the external moment occurs and what is its direction.

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